Just ran the numbers for exactly how badly Klay is doing vs his real life numbers:
fg% difference: -2.25%, -6.17%, -6.41%, -7.13%, -8.14%
efg% difference: +0.34% (!!!!), -3.51%, -3.72%, -6.49%, -4.70%
Everything I said initially remains true: he has an excellent efg%/usg% combo, solid defense, and superior turnover numbers. I have two theories as to why he has performed so poorly here, one of them being that I've been behind so much that he's launching a ton of desperation threes at the end of games, putting him in the individual possession penalty & thus lowering his overall fg% by two factors. The other one I'm going to keep to myself, as it plays a role in future strategies.